Tree of the month

Umbellularia californica,  Oregon Myrtle, Californian laurel

Native to the coast of California and Oregon, the
Californian laurel grows to a tree up to 16m tall in this country, to over 30m in its native range.  Its native climate is similar to that of the UK, and once established it is hardy here.  Nonetheless this tree is rare, found only in collections.  Our specimen (Priestfield catalogue number 205) was planted in 2004.

U. californica is the only remaining species in its family.  It is an evergreen tree.  The foliage is deep, glossy green which when crushed emits a rich, sweet, fruity aroma more powerful than that of the the Sweet Bay Laurus nobilis often used for culinary purposes.  If the leaves are used in cooking, half the quantity compared with the traditional bay should be used.  In summer when the oils evaporate faster, the scent can be detected some distance away. Native Americans are said to have used the leaves to treat headaches, toothaches, earaches, and sinus conditions (a leaf was inserted into a nostril), but it is also said to cause headaches (though none of us at the Arboretum has experienced this).  Whether as a cause or a cure is not clear, but the tree is sometimes known as the "Headache Tree".

Mature trees may produce "lignotubers", a swelling at the base of the trunk which stores food and buds that will sprout to regenerate the tree in the event of some major trauma such as loss of a main limb or even the main stem itself.

It flowers in late winter or very early spring, producing pale yellow flowers about 0.5cm in diameter in clusters of around 10.  These umbrella shaped  clusters give the plant its Latin name.  Fruit is green and egg shaped, and changes to a purple colour when ripe.  Both fruit and the nut it contains are reputedly edible (the nut when roasted).